package horstmann.ch02_mail;
/**
   A mailbox contains messages that can be listed, kept or discarded.
 */
public class Mailbox
{
	/**
      Creates Mailbox object.
      @param aPasscode passcode number
      @param aGreeting greeting string
	 */
	public Mailbox(String aPasscode, String aGreeting)
	{
		passcode = aPasscode;
		greeting = aGreeting;
		newMessages = new MessageQueue();
		keptMessages = new MessageQueue();
	}

	/**
      Check if the passcode is correct.
      @param aPasscode a passcode to check
      @return true if the supplied passcode matches the mailbox passcode
	 */
	public boolean checkPasscode(String aPasscode)
	{
		return aPasscode.equals(passcode);
	}

	/**
      Add a message to the mailbox.
      @param aMessage the message to be added
	 */
	public void addMessage(Message aMessage)
	{
		newMessages.add(aMessage);
	}

	/**
      Get the current message.
      @return the current message
	 */
	public Message getCurrentMessage()
	{
		if (newMessages.size() > 0)
			return newMessages.peek();
		else if (keptMessages.size() > 0)
			return keptMessages.peek();
		else
			return null;
	}

	/**
      Remove the current message from the mailbox.
      @return the message that has just been removed
	 */
	public Message removeCurrentMessage()
	{
		if (newMessages.size() > 0)
			return newMessages.remove();
		else if (keptMessages.size() > 0)
			return keptMessages.remove();
		else
			return null;
	}

	/**
      Save the current message
	 */
	public void saveCurrentMessage()
	{
		Message m = removeCurrentMessage();
		if (m != null)
			keptMessages.add(m);
	}

	/**
      Change mailbox's greeting.
      @param newGreeting the new greeting string
	 */
	public void setGreeting(String newGreeting)
	{
		greeting = newGreeting;
	}

	/**
      Change mailbox's passcode.
      @param newPasscode the new passcode
	 */
	public void setPasscode(String newPasscode)
	{
		passcode = newPasscode;
	}

	/**
      Get the mailbox's greeting.
      @return the greeting
	 */
	public String getGreeting()
	{
		return greeting;
	}

	private MessageQueue newMessages;
	private MessageQueue keptMessages;
	private String greeting;
	private String passcode;
}